Handles for bags designed for carrying products or articles are well known. Certain paper bags are provided with cardboard reinforcing handles secured to the paper bag by gluing or stapling. Larger paper bags are often provided with loop type carrying handles secured to reinforced areas of the paper bag by gluing or stapling.
Plastic bags, however, such as polyethylene or other thermoplastic bags, are usually too thin or are otherwise unsuitable for the attachment of handles by gluing or stapling. Such thermoplastic bags are typically provided with handles of several layers of the bag material heat welded to form a reinforced handle section thicker than the bag material. Such handles are typically manufactured of a compatible thermoplastic material and attached to the bag opening by heat welding. Such handles often provide for sealing of the bag opening through frictional engagement of pins or posts on one section of the handle assembly with holes or recesses in the complementary section of the handle assembly.
The seal provided by such posts and hole closure of the handle is of limited strength. The frictional engagement of the post with the hole is the only retaining force provided. When bags employing such a handle closure are used to carry heavy or bulky objects such closures tend to separate. Increasing the frictional engagement between the pin and hole can be helpful, but the use of an excessive frictional engagement results in a bag handle which is very difficult to open or close.
Often it is desirable to keep relatively heavy objects sealed within a carrier bag. For example, insulated bags that carry hot or cold products, such as food and drink, need to be sufficiently strong so as not to tear or open while maintaining the appropriate seal on the bag to achieve the insulation effect. Handles for such a carrier bag must be sufficiently strong to support the weight contained in the bag. The handle must also be capable of remaining in a closed position so that the carrier bag is sealed while being carried and does not tear open.
Various problems arise in both keeping the carrier bag airtight and providing the requisite strength in the carrier bag handle. It is especially difficult to keep the carrier bag airtight during the lifting of the bag because the free weight of the contents of the bag puts a downward pressure on the bag handle and the size of the contents of the bag creates outward horizontal forces on the handle, the bigger the size the larger the horizontal forces. As a result, the bag handle opens to expose the bag contents. If the carrier bag is being used as an insulation bag, the insulation effect is consequently broken.
Thus, there is a significant, unmet need for a carrier bag handle that both effectively seals the carrier bag in a closed position and is sufficiently strong to support a relatively heavy weight in the carrier bag. Moreover, it is especially desirable that the carrier bag handle be easy to use so that the carrier bag can be readily opened and closed as desired.